The present invention relates to a punching machine and, more particularly, to a portable punching machine, which can be conveniently carried to the job site to punch metal workpieces.
Various drilling machines and punching machines have been disclosed for use to make holes on metal sheet materials, for enabling metal sheet materials to be fastened together by rivets or screw bolts. When using a drilling machine to make holes on metal sheet materials, the peripheral edge of each processed hole is coarse and must be ground. Regular drilling machines and punching machines for making holes on metal sheet materials are commonly heavy and not portable. FIG. 12 shows a conventional punching machine 6 for punching metal sheet materials 5. Metal sheet materials must be carried to the drilling or punching machine and processed to provide the desired holes. After processing, the metal sheet materials are carried to the job site for installation. If the processed holes of the metal sheet materials do not fit, the worker shall have to carry the metal sheet materials to the drilling or punching machine for processing again.
The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a punching machine, which is portable. It is another object of the present invention to provide a portable punching machine, which can be used to punch holes on metal workpieces as well as to crimp metal workpieces. According to one embodiment of the present invention, the portable punching machine comprises a pneumatic cylinder controlled to reciprocate a piston rod, and a punching mechanism coupled driven by the piston rod to punch holes on a metal workpiece. The punching mechanism comprises a locating block fixedly fastened to the pneumatic cylinder, the locating block having a plurality of bottom notches and a center through hole adapted to receive the piston rod of the pneumatic cylinder, an actuating block and adapted to move the workpiece relative to the locating block upon movement of the piston rod, the actuating block having a plurality of peripheral side notches selectively coupled to the metal workpiece, and pairs of guide holes aligned at two sides of the peripheral side notches, and a plurality of punching tool assemblies adapted to make holes on the metal workpiece. Each punching tool assembly comprises a barrel mounted in one guide hole of the actuating block, a set of spring washers mounted in one bottom notch of the locating block, a punching rod mounted in one bottom notch of the locating block and inserted through the set of spring washers and the barrel, and a punching die mounted on one guide hole of the actuating block and aimed at the barrel. In another embodiment of the present invention, the locating block has a stepped crimping side facing the actuating block, and the actuating block has a stepped crimping side facing the stepped crimping side of the locating block and defining with the stepped crimping side a crimping mouth adapted to crimp the metal workpiece to be processed.